Optimized Dielectric Film for Maximum Sensitivity of Nearly Guided‐Wave Surface Plasmon Resonance Sensor

Abstract

In this paper, the dielectric film of the nearly guided-wave surface plasmon resonance (NGWSPR) sensor is optimized to achieve the maximum sensitivity. By optimizing the thickness of dielectric (Si, AlAs, TiO 2 , and Si 3 N 4 ) film in a NGWSPR sensor, the optimized sensitivity of the NGWSPR sensor can be obtained. The optimized sensitivity of the NGWSPR sensor with AlAs film is 5.43, 8.47, and 24.41% higher than that of the NGWSPR sensor with Si, TiO 2 , or Si 3 N 4 film respectively. In addition, by analyzing the electric field intensity of NGWSPR sensors, the origin of highest sensitivity achieved by the NGWSPR sensor with AlAs film is investigated. Furthermore, by comparing the optimized sensitivity of the NGWSPR sensor with different refractive index of dielectric film, the existence of optimal refractive index of dielectric film for the maximum sensitivity is confirmed. Besides, the effects of refractive index of prism on the optimal dielectric refractive index and the maximum sensitivity are also studied.